Radial flow rotary feeder for concrete aggregate



Aug. 28, 1951 COLBURN 2,565,546

RADIAL FLOW ROTARY FEEDER FOR CONCRETE AGGREGATE Filed Aug. 5, 1947 5 Sheets-Sheet l I N VEN TOR.

awzww Aug. 28, 1951 R. R. COLBURN RADIAL FLOW ROTARY FEEDER FOR CONCRETE AGGREGATE Filed Aug. 5, 1947 5 Sheets-Sheet 2 1951 R. R. COLBURN 2,565,546

RADIAL FLOW ROTARY FEEDER FOR CONCRETE AGGREGATE Filed Aug. 5, 1947 3 Sheets-Sheet 3 IN V EN TOR.

Patented Aug. 28, 1951 RADIAL FLOW ROTARY FEEDER FOR CONCRETE AGGREGATE Richard E. 'Colburn, Waterloo, Iowa Application August 5, 1947, Serial No. 766,353

Claims.

My present invention relates in general to improvements in the art of mixing and transporting various materials pneumatically, and relates more specifically to improvements in the construction and operation mechanism for automatically feeding a continuous stream of dry concrete aggregate or the like from a source of supply to a zone of utilization thereof.

The primary object of this invention is to provide an improved feeder for finely divided dry material such as concrete aggregate, which is simple and compact in construction and highly efficient in operation.

Various types of compressed air feeders for handling relatively gritty and abrasive dry concrete aggregate and similar materials, have heretofore been proposed and used commercially with varying degrees of success, but most of these prior feeding devices besides being relatively cumbersome and complicated, are not sufficiently durable to Withstand the abrasive action of the material and to avoid excessive air leakage for prolonged periods of time. It is preferable to have a feeding unit of this type portable so that it may be readily transferred from place to place, and the mechanism should therefore be as light and compact as possible, as well as being devoid of unnecessary complication. Then too, the surfaces of such feeding mechanisms, which are subjected to the action of the abrasive material flowing therealong, must be amply protected against excessive and rapid wear by means of relatively inexpensive and readily renewable wear resistant parts, in order to minimize the operating costs and to eliminate waste of the compressed air. None of the prior feeders of this type have met all of these requirements and they have therefore all proven objectionable for diverse reasons.

It is therefore a more specific object of my present invention to provide an improved feed unit for dry concrete aggregate, which besides meeting all of the above mentioned requirements, is adapted to deliver a uniform stream of the material to a nozzle or other zone of utilization.

Another specific object of the invention is to provide an improved automatic rotary feeder for dry finely divided abrasive material such as concrete aggregate, which is exceedingly simple and compact in construction and also comprises relatively few elements adapted to be quickly assembled or dismantled for inspection and renewal of parts. I

A further specific object of this invention is to provide a durable feeder for gritty substances,

' operable by compressed air, and in which all parts exposed to abrasion are well protected against rapid and excessive wear, and wherein leakage or undesirable escape of air under pressure is reduced to a minimum.

Still another specific object of my invention is to provide an improved feed mechanism wherein compressed fluid such as air or gas, is most effectively utilized to intimately mix and to continuously feed or transport finely divided dry granular material, with minimum attention on the part of the operator.

An additional specific object of my present invention is to provide an improved pneumatic feeder for concrete aggregate and the like, which may be manufactured and operated at relatively low cost, which is flexible in its adaptations, and all elements of which are conveniently accessible for lubrication, inspection and repairs.

Another specific object of the present invention is to provide a simplified rotary pneumatic measuring and feeding device for dry granular or pulverulent material, having a rotor provided with radial batch receiving and transfer pockets from which the successive batches are most effectively ejected by compressed air so as to produce a continuous and uniform stream flowing to the material utilizing zone.

These and other specific objects and advantages of my invention will be apparent from the following detailed description.

A clear conception of the features constituting my present improvement and of the construction and operation of a typical concrete ag regate feeder embodying the invention, may be had by referring to the drawings accompanying and forming a part of this specification in which like reference characters designate the same or similar parts in the various views.

Fig. 1 is a vertical section through a typical concrete aggregate feeder embodying the invention, taken centrally through the major portion of the unit, but along the irregular line l-l of Fig. 3 through the rotor;

Fig. 2 is an end elevation and partial transverse section through the same feeding unit, the section through the rotor having been taken along the line 2-2 of Fig. 1;

Fig. 3 is a side elevational view of the rotor alone of the feeder shown in Figs. 1 and 2;

3 the feed mechanism, taken through the rotor seal along the line 5-5 of Fig. 2.

While the invention has been shown and described herein as being advantageously applicable to and embodied in a typical portable concrete aggregate feeder adapted to deliver a constant and uniform stream of dry granular or pulverulent material through a discharge conduit with the aid of compressed air; it is not my desire or intention to unnecessarily restrict the scope or the utility of the improvement by virtue of this limited disclosure.

Referring to the drawings, the improved portable concrete aggregate feeding unit shown, comprises in general a sturdy main frame 8 having a base portion 9 adapted to be mounted upon a truck for convenient transportation, and also having a horizontal central tubular casing l8 mounted therein and forming a compressed air supply chamber H; an annular rotor 12 journalled for rotation upon the medial portion of the casing it within the frame 8, and having two similar annular series of outwardly open radial pockets [4 each provided with an ofi-set passage H) at its inner end communicable with the chamber I f through an adjacent port IE formed in the casing ID; a dry concrete aggregate supply hopper I! mounted upon the main frame 8 centrally above the rotor l2 and casing I8, and having a lower outlet I8 communicable with the successive rotor pockets [-4- to admit batches of material 23 thereto; a material discharge casing 2| mounted upon one side of the frame 8 remote from the hopper outlet [8 and in horizontal alinement with the air supply ports l6, and forming a discharge conduit 22 also communicable with the successive rotor pockets [4 to receive the batches of material therefrom; an arcuate rubber seal plate 23 coacting with the periphery of the rotor [2 between the hopper outlet I 8 and the conduit 22, and being resiliently urged against the rotor surface; and a driving pinion 24 carried by a horizontal propelling shaft 25 journalled in the frame 8, and coacting with an annular internal gear 26 formed in one end of the rotor [2, to constantly revolve the rotor in the direction indicated by the arrow in Fig. 2. I

The main frame and rotor housing 8 may be formed of any suitable material and of separable sections adapted to be clamped together by means of bolts 28, and the lower portion of the frame 8 is preferably provided with a large inspection and clean-out opening 29 for the empty rotor pockets M and passages [5, as shown in Fig. 1. The cylindrical tubular casing It which forms the air supply chamber ll, may be firmly mounted and secured within the main frame a with the aid of opposite end plates 3!, 32 secured to the frame by means of cap-screws 3t; and one end of the casing I0 is provided with a closure plug 33 having an air supply fitting 34 associated therewith and communicating with any suitable source of compressed air supply, while the other end of this casing I0 is sealed by a solid plug 35. The chamher [I is thus sealed against possible leakage or escape of compressed air, except through the ports 16.

The central bore of the material transfer rotor I2 is preferably provided with a renewable bearing sleeve 36 which snugly embraces and is rotatable about the medial portion of the tubular casing l0, and suitable packings 3! which are held in place by screw plugs 38 are provided between the rotor l2 and casing ID at the opposite ends of the bearing sleeve 36, as illustrated in Fig.

1. The two series of pockets Hi formed in the rotor l2 may be of similar formation, and the successive pockets of each series may be spaced apart like distances, but as depicted in Figs. 2 and 3, the pockets [4 of one series are staggered relative to those of the other series so that the radial centerlines of the adjacent pockets of the two series do not lie in the same radial plane relati've to the rotor axis. The outer open ends of the pockets M are of approximately the same width measured circumferentially of the rotor 12 as the corresponding width of the inlet end of the discharge conduit 22, and the staggering or off-setting of the pockets [4 of the two series insures communication between the conduit 22 and at least one pocket [4 of the rotor at all times.

The compressed air supply passages l5 which communicate with the inner ends of the radial pockets l4 may also be disposed radially relative to the rotor axis, but they are preferably off-set relative to their respective pockets as depicted in Figs. 1, 2 and 3, in order to prevent the passages l5 from becoming unduly filled with and perhaps clogged by finely divided material 29 when batches of this material are deposited within the pockets. The passages [5 may be formed directly in the rotor l2, and the latter is provided with opposite outwardly extending end flanges it, ii having inwardly inclined or tapered adjacent side surfaces merging with the cylindrical medial portion of the rotor in which the pockets i l are formed. The passages l5 and the ports It with which these passages are communicable, may be located near the rotor flanges til, @I as shown. and the ports it which are disposed in horizontal alinement with the discharge conduit should be of sufficient circumferential length to effect compressed air admission from the supply chamber II to the successive pockets It whenever the outer open pocket ends are brought into open communication with the conduit 22.

The material supply hopper ll may be secured to the upper portion of the main rotor housing frame 8 in any suitable manner, as by screws and the lower end of the hopper il in which the material delivery opening I8 is formed, rather snugly coacts with the tapered surfaces of the rotor flanges 40, 4| and with the cylindrical intervening portion of the rotor 12. The supply of material 29 within the hopper Il may be continuously stirred by means of a rotary agitator d3 which may be constantly driven from the main propelling shaft 25 of the feeding unit with the aid of V-belt drive 44 or the like, thereby thoroughly mixing the concrete aggregate and also preventing bridging of the hopper outlet opening [8. The agitator 43 may be of any desired type, and may be journalled for rotation in bearings 45 carried by the main frame 3, and the material 20 is delivered from the hopper l'i to the successive rotor pockets I l by gravity alone.

The lower discharge or outlet opening [8 of the hopper I! is preferably of such length measured circumferentially of the rotor 12, that a considerable number of the pockets i l will simultaneously communicate with the hopper, thus insuring substantial filling of the successive pool:- ets. The distance between the hopper outlet H3 and the final discharge conduit 22 measured circumferentially of the rotor l2, should also be at least equal to, and preferably somewhat greater than the width of a pocket plus twice the distancebetween the peripheral openings of the successive pockets [4, in order toprevent escape of compressed air from the conduit'22 into .the hopper I1, and while the packings 31 will eliminate undesirable leakage and escape of compressed air along the casing I I], the periphery of the rotor I2 along the space intervening between the hopper I1 and discharge casing 2I must also be effectively sealed against such leakage.

The arcuate rubber sealing plate 23 which coacts with the rotor periphery between the flanges 40, H and with the tapered side surfaces of these flanges, performs the function of sealing the rotor periphery against possible leakage; and this renewable flexible sealing plate 23 is vulcanized to a metal backing plate 41 which is adapted to snugly engage an arcuate breast plate 48 to which the discharge casing 2| is 'firmly secured by cap screws 49. The breast plate 48 and the plates 41, 23 are loosely confined within a side recess 50 of the main frame 8, and. are held within this recess 50 by a pair of levers 5| pivot/ally suspended from the frame 3 by pins 52 and carrying cams 53 at their medial portions which are cooperable with central bosses 54 formed on the plate 48, as shown in Figs. 1, 4 and 5. The swinging extremities of the levers 5| coact with helical compression springs 56 which embrace studs 5'! secured to the frame B,'a11d the action of these springs 55 may be varied with the aid of adjusting nuts 58 coacting with threads on the studs 51, thereby providing means for resiliently urging the plates 23, 41, 48 toward the rotor periphery while also permitting convenient removal of the sealing elements.

The final material discharge casing 22 is pref- ,erably formed of wear resistant relatively flexible rubber so that it may be distorted laterally, and this casing is provided at its delivery end with a metal fitting 65 adapted to provide a connection with the usual flexible hose to which the nozzle or other concrete aggregate utilizing zone is attached. The conduit 22 is preferably tapered as shown in order to augment the velocity of the air and material mixture delivered through the casing 2 I; and the rotor and agitator propelling shaft 25 which may be driven from any suitable source, is journalled in a bearing 6| carriedby the side plate M of the frame 8, while the driving pinion 24 coacts with internal gear teeth 26 preferably formed within the widest end flange 40 of the rotor I2.

When the improved concrete aggregate feeding unit has been properly constructed and assembled as hereinabove described, the driving shaft 25 may be connected to a suitable source of power, the compressed air supply fitting 34 should be connected to a source of compressed air through a shut-off valve, the final discharge fitting 60 may be connected to a nozzle or the like, the hopper I! should be abundantly supplied with material 25, and the various parts of the mechanism may be properly lubricated and adjusted. As the rotor I2 subsequently revolves in the direction of the arrow in Fig. 2, the'successive pockets I4 of both revolving series will be filled by gravity with batches of the material while advancing beneath the hopper outlet I8, and the agitator '43 will insure such filling and will prevent the material 20 from bridging across the opening I8.

The successive material ladenpockets I4 will thereafter be transported along the arcuate rubber seal plate 23 and will be momentarily maintained sealed from communication with the hopper outlet I8 and with the discharge conduit 22, whereupon the advancing pockets I4 will be brought successively into open communication with the discharge conduit :22. .'.Simultaneously with the establishment of communication between the outer open end of each tapered pocket I4 and the conduit 22, the passage I5 at the inner end of the pocket will be brought into communication with the compressed air supply chamber II through the adjacent port I5, and compressed air will then flow outwardly through the passage I5 and through the corresponding pocket I4 and will eject the batch of material 20 therefrom into the discharge conduit 22.

The successive pockets I4 are thus automati cally emptied by compressed air, and due to the staggering of the pockets I4 of the several series, material 20 will be injected into the conduit 22 continuously as the rotor I2 revolves. The outwardly tapering formation of the transfer pockets I4 insures complete ejection of the material batches therefrom, and the off-set disposition of the passages I5 prevents these passages from becoming clogged with material 20; and while the material is flowing through the tapered discharge conduit 22 its velocity is augmented and the particles are intimately mixed so as to produce a homogeneous and uniform stream of aggregate which is promptly delivered to the cement gun or other source of utilization.

The springs 56 serve to press the rubber seal plate 23 with the degree of pressure necessary to produce effective sealing, and this pressure may be readily varied by adjusting the nuts 58 upon the studs 51. The cams 53 may also be quickly manipulated with the aid of their actuating levers, to entirely relieve the pressure on the plates 23, 41, 48; and by removing the nuts 58 and springs 56 from the studs 51 and subsequently swinging the levers 5I out of the way, the plates 23, 41, 48 and the casing 2I may be entirely withdrawn from the recess 5!] of the main frame 8. If the pockets I4 and ports I5 should become clogged, they may be cleaned through the lower inspection opening 29 of the main frame; and the rotor I2 may be freely removed from within the housing frame 8 upon. removal of the seal plates and release of the hopper retaining screws 42, by merely removing the bolts 30 and separating the main frame sections.

From the foregoing detailed description it will be apparent that my present invention provides an improved automatic pneumatically actuated concrete aggregate feeding unit, which besides being exceedingly simple, compact and durable in construction, is also highly efficient in operation and flexible in its adaptations. The improved mechanism is obviously adapted to transfer and to deliver a uniform continuous stream of material 20 from the supply hopper I! to the discharge conduit 22 while subjecting the parts to minimum abrasion and resultant wear, and undesirable leakage or escape of compressed air is positively eliminated. The lateral flexibility of the discharge casing 2| is especially useful when this casing is attached to a delivery hose; and by forming the casing 2| and the seal plate 23 of soft and flexible rubber, the wear on these elements is minimized and frequent replacements and repairs are avoided.

The radial disposition and outward enlargement or tapering of the pockets I4 and the offsetting of the air injection passages I5, is im portant in order to eliminate undesirable clog ging; and the provision of several annular relatively staggered series of pockets I4 is likewise important in order to insure continuity of the stream of material 20 delivered from the assem- 7, blage. The improved driving mechanism for the rotor 14 and agitator 43 is obviously very simple but effective, and the driving members are amply protected against damage; and the entire unit may be manufactured and operated at moderate cost for diverse uses.

It should be understood that it is not desired to limit this invention to the exact details of construction and operation herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art; and it is also contemplated that specific descriptive terms used herein be given the broadest possible interpretation con sistent with the disclosure.

I claim:

1. In a concrete aggregate feeder, a rotor having an annular series of radial outwardly open pockets each provided near its inner end with an off-set passage formed to prevent inward flow of aggregate beyond the pocket, a supply hopper for delivering batches of material into said pockets through their outer open ends, a casing forming a discharge conduit communicable with the outer open ends of the successive pockets remote from said hopper, and means for injecting air into the inner ends of said pockets through said passages when the outer pocket ends are in communication with said opening to eject the material batches from the pockets.

2. In a concrete aggregate feeder, a rotor having several independent annular series of radial outwardly open pockets each provided near its inner end with a passage formed to prevent inward flow of aggregate beyond the pocket, a supply hopper for delivering batches of material into the open outer ends of the successive pockets of all of said series, a casing forming a discharge conduit communicable with said open outer pocket ends remote from said hopper, the pockets of the several series being staggered circumferentially of the rotor to constantly maintain at least two of the pockets in communication with said opening, and means for injecting air into said pockets through said passages when the corresponding pockets are in communication with said opening.

3. In a concrete aggregate feeder, a rotor hav=- ing several laterally adjacent staggered series of equally spaced outwardly open pockets each provided near its inner end with passage formed to prevent inward flow of aggregate beyond the pocket, a supply hopper for delivering batches of material into the successive pockets, a casing forming a discharge conduit communicable with the outer open ends of the successive pockets, and a compressed air supply chamber within said rotor having ports alineable with. the successive passages of all of said. series to inject air through the corresponding pockets whenever the open pocket ends are brought into communication with said conduit.

4. In a concrete aggregate feeder, a rotor having an annular series of pockets open at the rotor periphery and each provided near its inner end with a lateral passage formed to prevent inward flow of aggregate beyond the pocket, a supply hopper for delivering concrete aggregate into the successive pockets during revolution of said rotor, a casing forming a discharge conduit remote from said hopper and which is communicable with said pockets at said rotor periphery, means for injecting compressed air through said passages into the successive pockets when in communication with said conduit, and a rubber seal coacting with the periphery of said rotor between said hopper and said conduit for preventing escape of compressed air from conduit into the hopper.

5. In a concrete aggregate feeder, an annular rotor having a series of outwardly open radial pockets and being provided with outwardly extending flanges at the opposite sides of said series, a supply hopper for delivering concrete aggregate by gravity into the successive pockets through their outer open ends, a casing forming a discharge conduit communicable with the outer ends of the successive material laden pockets, means for injecting compressed air outwardly through said pockets while in communication with said conduit, and driving means coacting with said rotor within one of said flanges for revolving said pockets about the rotor axis.

6. In a concrete aggregate feeder, a rotor having two relatively staggered annular series of pockets open at the rotor periphery, the inner end of each pocket being provided with a laterally off-set passage formed to prevent inward flow of aggregate beyond the pocket, a supply hopper for delivering concrete aggregate into the successive pockets of both series during revolution of said rotor, a casing forming a discharge conduit remote from said hopper and which is communicable with the pockets of both series at said rotor periphery, means for injecting compressed air through said passages into the successive pockets of both series when in communication with said conduit, and a rubber seal coacting with the perip ery of said rotor between said hopper and said conduit for preventing escape of compressed air from the conduit into the hopper.

7. In a concrete aggregate feeder, a rotor having an annular series of pockets open at the rotor periphery and each provided near its inner end with a passage formed to prevent inward flow of aggregate beyond the pocket, a frame providing a housing for said rotor, a supply hopper for delivering concrete aggregate into the successive pockets during revolution of said rotor, a flexible rubber casing forming a discharge conduit remote from said hopper and which is communicable with the outer open ends of said pockets, means for injecting compressed air through said passages into the successive pockets when in communication with said conduit, an arcuate rubber seal coacting with the periphery of said rotor between said hopper and said conduit, a rigid arcuate breast plate coacting with the exterior of said seal and providing a direct support for said rubber casing, and means for detachably attaching said plate to said rotor housing.

8. In a concrete aggregate feeder, a rotor having several relatively staggered annular series of outwardly enlarging radial pockets each provided near its inner end with an off-set passage formed to prevent inward flow of aggregate beyond the pocket, a supply hopper for delivering batches of material into said pockets, a casing forming a discharge conduit communicable with the larger outer open ends of said pockets remote from said hopper, and means for injecting compressed air into the smaller inner ends of the successive pockets to eject said batches from said pockets into said conduit.

9. In a continuous feeder for granular material, a rotor having an annular series of radial outwardly open pockets each provided with an air injection passage having its outlet end off-set relative to the adjacent pocket to prevent inward flow of granular material beyond the pocket and having a radially disposed inlet end, a supply hopper for delivering batches of material into said pockets through their outer open ends, a casing forming a discharge conduit communicable with the outer open ends of the successive pockets remote from said hopper, and means for injecting air into the inner ends of said pockets through said passages when the outer pocket ends are in communication with said opening to eject the material batches from the pockets.

10. In a continuous feeder for granular material, a rotor having several relatively staggered annular series of radial outwardly open pockets each provided with an air injection passage having its outlet end off-set relative to the adjacent pocket to prevent inward flow of granular material beyond the pocket and having a radially disposed inlet end, a supply hopper for delivering batches of material into said pockets, a casing forming a discharge conduit communicable with the outer open ends of said pockets remote from 10 said hopper, and means for injecting compressed air into the inner ends of the successive pockets through said passages to eject said batches from said pockets into said conduit.

RICHARD R. COLBURN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,041,548 Wilson Oct. 15, 1912 1,096,785 Jensen May 12, 1914 1,777,043 Lanhoffer Sept. 30, 1930 1,953,091 Westberg Apr. 3, 1934 1,997,791 Hoberg Apr. 16, 1935 FOREIGN PATENTS Number Country Date 370,879 Germany Aug. 7, 1923 

